Tables having tops which are vertically adjustable have proved useful in many applications, particularly for overbed tables utilized in hospitals and similar situations where it is desirable to have a table which may be adjusted for use by a person in a bed or a chair.
An important part of a vertically adjustable table is the mechanism which releasably locks the table top at a selected vertical position, as this mechanism must dependably prevent unintended downward movement of the table top relative to the base. Various types of locking mechanisms have previously been developed, for example those disclosed in U.S. Pat. Nos. 2,685,487, 3,715,997 and 3,999,492. Although these mechanisms have generally been adequate for retaining the table top at selected vertical positions, they have not been satisfactory in all respects. In particular, they have required a relatively large number of parts and the necessary assembly of such parts, and/or have involved relatively complex machining of certain parts. Accordingly, the tables utilizing these locking mechanisms have been relatively expensive to manufacture and assemble.
Accordingly, it is an object of the present invention to provide a locking mechanism for a vertically adjustable table which is simple and utilizes a minimum number of structural parts, and which is therefore inexpensive to manufacture and assemble.
A further object of the present invention is to provide a locking mechanism, as aforesaid, which will securely and dependably retain the table top in a selected vertical position.
A further object of the present invention is to provide a locking mechanism, as aforesaid, which is durable, is small in size and weight, and requires little or no maintenance.